Covid (@UCSF) Chronicles, Day 237 Didn't plan to tweet today, but can’t resist a few quick takes on @pfizer vaccine news https://t.co/CUytUmMTRg

Covid (@UCSF) Chronicles, Day 237 Didn't plan to tweet today, but can’t resist a few quick takes on @pfizer vaccine news https://t.co/CUytUmMTRg